Among other forms of bacteria possess ing pathogenic properties encountered we may mention the staphylococcus pyog,enes, the bacillus pyocyaneus, the bacillus mesentericus, and the bacillus enteritidis (Giirtner). Such forms prob ably more or less modify the symptoms in special cases.
Although at birth the contents of the digestive tract are sterile, bacterial in fection is brought about within the first twelve hours of life through the medium of the atmospheric air, which the infant swallows in large quantities. The vari ous micro-organisms thus introduced into the system thrive and multiply in the mucus and undigested food which soon fill the intestine, and are constantly reinforced in numbers and diversified in species by the ingestion of contaminated milk or the swallowed secretions of the mouth. The danger which arises from these natural sources of infection is greatly increased by the fact that during infant-life the gastric juice is incapable of exerting any decided control over mi crobic growth, owing to its comparative deficiency in free hydrochloric acid. The entrance of undigested and fermenting material into the intestine induces violent peristalsis, with the result that the infant suffers from colic and diar rhoea until the bowel has succeeded in ridding itself of its irritating contents. If proper means are taken to assist Nature and to prevent a recurrence of the disorder, the stools soon resume their normal appearance and perfect recov ery ensues. But if these evidences of digestive derangement are overlooked, gastro-intestinal catarrh supervenes. This inflammatory condition probably arises from direct irritation of the mu cous membrane of the digestive tract by acid products of fermentation, and, since it is always accompanied by a diminu tion in the secretion of hydrochloric acid, gastric digestion becomes greatly enfeebled, and the various bacteria are afforded an unlimited scope of action. Within a short period of time the intes tine becomes affected in a similar man ner, and the child begins to lose flesh and strength and to present all the symp toms characteristic of chronic intestinal catarrh. The third and last stage of the disease is marked by a more or less ex tensive cirrhosis of the mucous mem brane of the digestive tract, often asso ciated with the follicular ulceration of the colon. The diarrhoea continues and the stools are largely mixed with mucus or streaked with blood; the marasmus increases, and death finally ensues either from exhaustion or from some nervous phenomena due to the absorption of toxins from the alimentary tract. W.
Soltau Fenwick (Brit. Med. Jour., Dec. 21, '95).
[Fifteen varieties of bacteria have been isolated from the stools of children suf fering from summer diarrhoea, in addi tion to the B. coli commune and B. lactis aerogenes of Escherich, and the forms are not yet exhausted. The great majority of the bacteria belonged to the group classed as saprophytic. No constant form was found, and no one form pre dominated in a large proportion of the cases. Baginsky, Corr. Ed., Annual, '91.] Study of the stools clearly showing that no single species of micro-organism is responsible for the disease, and also, in a general way, that the character of the passages and the nature of the systemic disturbance conform to the character of the intestinal infection.
In a considerable number of these cases the obligatory milk-fmces bacteria were found to be the chief bacterial ingredient of the stools. These were for the most part mild cases, of short duration, and usually without apparent toxic symp toms. The stools were sometimes very frequent, were usually acid in reaction, and lacked uniformity of consistence, having been often lumpy. They con tained no leucocytes. Twenty-four cases of this type were studied. Bacillus coli communis and bacillus titans aerogenes preponderated. Other bacteria when present appeared in very small numbers and were apparently insignificant. In all these cases bacillus coli preponderated in the stools over bacillus lactic.
In another set of cases, represented by six only of the ninety-two, while the obli gatory milk-fmces bacteria, were greatly increased in number, the inconstant bac teria of the normal intestinal contents preponderated and appeared to play an important role in the induction of the symptoms. Thus, in three of the cases "bacillus a" was the most notable teat tire, and in one each "bacillus x," "bacil lus y," and "bacillus d.'"fhese are the designations applied by the writer to four of the numerous inconstant milk faeces bacteria of infants described by him in a former paper, several of which were found to be pathogenic to animals, and have since been shown by Vaughan to elaborate toxic substances when grown in broth. These eases were all severe and presented evident toxic symptoms. The stools were frequent in some, in frequent in others, and varied much in consistence. They often had a decidedly putrid odor. One of these cases in which "bacillus x" preponderated was fatal.